Limits of near-coloring of sparse graphs - LIRMM - Laboratoire d’Informatique, de Robotique et de Microélectronique de Montpellier
Conference Papers Year : 2012

Limits of near-coloring of sparse graphs

Abstract

Let a, b, d be non-negative integers. A graph G is (d, a, b)∗ -colorable if its vertex set can be partitioned into a + b sets I1,...,Ia,O1,...,Ob such that the graph G[Ii] induced by Ii has maximum degree at most d for 1 ≤ i ≤ a, while the graph G[Oi] induced by Oi is an edgeless graph for 1 ≤ i ≤ b. In this paper, we give two real-valued functions f and g such that any graph with maximum average degree at most f(d, a, b) is (d, a, b)∗ -colorable, and there exist non- (d, a, b)∗ -colorable graphs with average degree at most g(d, a, b). Both these functions converge (by lower values) to 2a + b when d tends to infinity. Counterintuitively, this implies that allowing a color to be of type Ii even for a large degree d increases the maximum average degree that guarantees the existence of a valid coloring only by 1. Using a color of type Ii (even with a very large degree d) is somehow less powerful than using two colors of type Oi (two stable sets).
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Dates and versions

lirmm-00782851 , version 1 (30-01-2013)

Identifiers

  • HAL Id : lirmm-00782851 , version 1

Cite

Mickaël Montassier. Limits of near-coloring of sparse graphs. 2012 International Conference on Graph Theory, Combinatorics and Applications, Oct 2012, Zhejiang, China. ⟨lirmm-00782851⟩
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